1. Field of Invention
The present invention relates to a probe and, in particular, to a scanning thermal probe.
2. Related Art
Atomic force microscopy (AFM), also called scanning probe microscopy (SPM), includes the scanning mechanism and operation as well as the fine probe mechanism, so it has become one of the most important instruments in the fields of nano-technology and biomedical research.
FIG. 1 is a schematic diagram showing a scanning probe to detect a sample surface. As shown in FIG. 1, when the surface of a sample 11 is scanned by the probe 12, a light-emitting element 13 outputs a light beam (e.g. a laser) to irradiate a cantilever 121 of the probe 12, and the light beam is reflected and received by a light sensing element 14 (e.g. a photo diode). The control feedback circuit 15 receives the signal transformed by the light sensing element 14 and feeds back to control the movement of a scan mechanism 16 for adjusting the position of the sample 11. Accordingly, the interaction between the tip 122 and the surface of the sample 11 can be maintained at a certain value. The adjustment data for adjusting the position of the sample 11 is referring to the interaction data between the tip 122 and the surface of the sample 11, which is usually corresponding to the surface geography of the sample 11.
The bottleneck of the atomic force microscopy applied to nano-technology and biomedical research is mainly the design and fabrication of new probe. Therefore, the scan probe is the core technique of the atomic force microscopy. In addition, the scanning thermal probe microscopy (SThM) is another technology based on the atomic force microscopy. The different therebetween is that the scanning thermal probe microscopy includes a thermal probe, which can detect the temperature distribution of the sample surface. Due to this novel technology, the scale of thermal analyzing can reach micrometers or sub-micrometers.
However, the scanning thermal probe is usually manufactured by silicon MEMS processes. That is, the tip, heater and cantilever are all made of silicon materials. Although the silicon MEMS processes as well as the quality control thereof are easier, there are still limitations on the tip wearing, effective temperature range of the heater, and the highest measuring temperature. In addition, when using the tip of the thermal probe to scan, the tip and the sample surface can have interaction, which results in the wearing of the tip. If the curvature of the tip increases, the resolution of the image is affected. If the tip must be replaced for providing different functions, the conventional thermal probe does not provide the function for replacing the tip only, so that the entire thermal probe should be replaced. Besides, the conventional tip, heater and cantilever are all made of silicon material, so that the user can not select the optimum combination of the tip, heater and cantilever based on his/her requirement.
Therefore, it is an important subject to provide a thermal probe having the replaceable tip, so that the optimum combination of the tip, heater and cantilever can be selected according to the demands.